Synthetic resins are widely used as building materials because they have good moldability and enable mass production of uniform products. However, since synthetic resins easily melt or burn, generating gas or smoke, materials with a low level of smoke emission and excellent fire resistance have been desired for safety in case of fire. In particular, door or window sashes require a material that is flame-retardant, and that can also retain the shapes of door or window sashes even during fire and prevent fire from reaching outside (back side) the doors or windows.
As a material that meets such a demand, Patent Literature 1 discloses a chlorinated polyvinyl chloride resin composition capable of long-time stable extrusion molding of a profile molded product having a complicated cross-sectional shape such as a sash. The chlorinated polyvinyl chloride resin composition comprises 100 parts by weight of a chlorinated polyvinyl chloride resin, 3 to 300 parts by weight of thermally expandable graphite, 3 to 300 parts by weight of an inorganic filler, and 20 to 200 parts by weight of a plasticizer, and does not contain a phosphorus compound (excluding a phosphate plasticizer).